This proposal seeks to develop new materials and approaches to the design of ultrathin films that permit spatial and temporal control over the release of DNA from surfaces. The proposed research seeks to test the hypothesis that ultrathin multilayered films composed of alternating layers of plasmid DNA and degradable polyamines can be used to promote broad and tunable control over surface-mediated cell transfect ion in vitro and in vivo. Our approach is founded on preliminary observations that ultrathin films (e.g., 100 nm thick) fabricated from alternating layers of DNA and degradable cationic polymers promote cell transfect ion when placed in contact with cells and tissues. These critical observations suggest the basis of general methods that permit spatial and temporal control over the release of DNA in vitro and facile new methods for the coating and localized delivery of DNA from the surfaces of indwelling devices in vivo. Our preliminary investigations validate the principles required to exploit ultrathin multilayered films for the surface-mediated delivery of DNA. The following Specific Aims are designed to systematically evaluate our hypothesis and evaluate the full potential of this approach. They are: 1) To characterize the influence of polymer structure on rates of release of DNA and the structure and morphology of DNA released from ultrathin films fabricated from alternating layers of plasmid DNA and degradable polyamines;2) To investigate the influence of polymer structure and film architecture on levels of cell transfect ion and viability in vitro when objects coated with ultrathin films are placed in contact with cells;and 3) To demonstrate that materials developed and evaluated under Aims 1 and 2 can be used to coat indwelling devices such as intravascular stents, and that film-coated stents can be used transfect vascular tissue in vivo when implanted in the arteries of rabbits and pigs. We envisage the outcomes of the proposed research as having substantial fundamental and applied impacts by (i) providing new materials and tools for basic biomedical research and surface-mediated transfection in vitro, (ii) by developing robust new methods for the localized delivery of DNA from indwelling devices in vivo, and (iii) by providing a foundation for future research and the selection of materials with properties (e.g., specific release profiles) suited for the evaluation of therapeutic gene candidates directed toward a broad range of different therapeutic outcomes. Public Health Relevance: The potential impact of methods that provide control over the release of DNA from surfaces ranges from applications in basic biomedical research to, ultimately, the realization of gene-based therapies in the clinic. The research described in this proposal will impact public health by providing new tools for surface-mediated DNA delivery in vitro and new methods for localized delivery of DNA from indwelling devices in vivo that could improve the efficacies and reduce the side effects of gene-based therapies.